Dosage units in the form of tablets are prepared by compressing a formulation containing a medicinal substance or drug and other ingredients, such as excipients selected for properties which enhance the production and use of the tablet. There are currently three known basic methods for preparing tablet granulations. These are wet granulation, dry granulation and direct compression. Both wet and dry granulations involve the formation of an agglomerate for feeding to a die cavity. Direct compression usually involves compressing a powder blend of an active ingredient with suitable excipients.
Other methods of preparing feedstock for preparing compression dosage units have been disclosed in the above-referenced copending applications as well as in copending, commonly owned U.S. application Ser. No. 08/194,682 filed Feb. 10, 1994. Each of these applications are incorporated herein by reference.
U.S. application Ser. No. 08/194,682 discloses a method of making a solid comestible by compressing shearform matrix masses sufficiently to form a comestible compression unit. U.S. application Ser. No. 08/259,496 discloses a method of preparing a quick dissolve comestible unit by mixing uncured shearform matrix and an additive, molding a unit dosage form therefrom, and curing the shearform matrix. Finally, U.S. application Ser. No. 08/259,258 discloses a method of preparing quick dissolve comestible units by initiating crystallization of shearform matrix, and combining, either before or after initiating crystallization, an additive with the shearform matrix to form flowable, compactible micro-particulates. Finally, the micro-particulate medium is compacted to form the quick dissolve comestible unit. In each of these disclosures, the tableting medium is prepared initially by use of shearform matrix. In most cases a quick dissolve tablet can be produced by providing a compressed body which is of low density and capable of being disintegrated and dispersed relatively rapidly, and in many cases, instantaneously.
Tableting processes known today in the art generally include the use of a machine which includes opposing punches and cavities into which a tableting medium can be directed and subjected to compression between the punches. See, for example, U.S. Pat. No. 4,943,227; U.S. Pat. No. 4,880,373; U.S. Pat. No. 2,214,505 and U.S. Pat. No. 2,068,619. Other references which disclose different shapes of dosage units are U.S. Pat. No. 4,493,822, U.S. Pat. No. 4,376,111, and an excerpt from The Consumer Guide for "Prescription Drugs," p. 194-208, Publications International, Ltd. (1990).
In the manufacturing of low density tablets, a newly formed tablet is relatively fragile and must go through a curing process over time where the tablet hardens so that it can be easily handled, packaged and distributed. Quite often attempts to package a newly formed tablet result in damage to the tablet itself. This necessitates waiting a period of time before packaging the tablet or taking extra precautionary steps in the handling of the tablet during the packaging phase. Each of these solutions obviously increases the difficulty and cost involved in forming and packaging tablets.
It is therefore desirable to provide a method and apparatus for enabling the formation of tablets directly in the product package. This will enable the tablet to be formed and packaged without handling delay or extra processing steps.